A Thai court postponed on Monday for a second time an extradition hearing for a Russian businessman charged with arms smuggling after his new Thai lawyer was unable to attend court, national media said.

Last month, the court postponed Viktor Bout's first extradition hearing as his Thai lawyer, Lak Nitiwatanavichan, had developed "a heart problem." Vipon Kititasnaisornchai, who recently took over as Bout's lawyer, on Monday asked the Bangkok Criminal Court to postpone the hearing as he already had another case scheduled.

The hearing has now been delayed until September 22.

Bout, 41, was arrested in March in Bangkok during a joint police operation led by agents from the U.S. Drug Enforcement Administration (DEA).

DEA prosecutors claim that Bout conspired with others to sell millions of dollars worth of weapons to the Revolutionary Armed Forces of Colombia, a leftist group listed by the U.S. as a terrorist organization.

Thailand received in early May a formal request from Washington to extradite Bout to the U.S., where he has been indicted on four charges: conspiracy to kill Americans and U.S. officers or employees, conspiring to provide material support to terrorists and conspiring to acquire and use an anti-aircraft missile.

"If everything goes according to the law, and based on what the U.S. side is proposing and what we are proposing, then the extradition request should be denied," Bout's Russian lawyer, Yan Dasgupta, commented.

Dasgupta, who claims that the investigation against Bout was politically motivated, also said that the "crime that Bout committed or planned to commit" was not a crime according to the Thai law.

Western law enforcement agencies consider Bout to be "the most prominent foreign businessman" involved in trafficking arms to UN-embargoed destinations.

UN reports say Bout set up a network of more than 50 cargo aircraft around the world to facilitate his arms shipments, earning the nickname 'merchant of death.'